Munitions systems (i.e. munitions) are comprised of several components including “munitions structure”, a warhead (comprising conventional explosives), fuses, stability components (e.g. wings or sabot), and a propulsion unit/propellant in the case self-propelled munitions such as missiles. Warheads utilize one or both of the following general mechanisms of lethality to achieve target destruction:                i) Blast, rapid pressure increase in the ambient environment (including air and/or underwater burst) which is facilitated by the release of chemical energy of conventional explosives;        ii) Impact of a hard projectile body with a high degree of kinetic energy.        
Accordingly, most warheads (excluding pure kinetic energy penetrators) incorporate a significant amount of conventional explosives to provide blast and/or to provide kinetic energy to projectile bodies. These are generally known as explosives-based warheads. In ordinary munitions systems, a warhead is the primary lethality component, that is, the primary component designed to impart damage to the target. “Munitions structure,” on the other hand, is a structure with a primary function of holding together the warhead and other components of the munitions system. “Munitions structure” is typically an inert material, such as steel or brass, and is generally regarded as parasitic structure/weight with minimal or no direct lethality effect.
Munitions systems with explosives-based warheads are designed to carry a warhead to the vicinity of a target (the target vicinity) and then initiate the warhead's explosive(s) using a fuse mechanism to create an explosion at a desired time and location. This explosion causes rapid pressure increase in the target vicinity, and the resulting blast imparts damage to the target. There are several issues for munitions systems using conventional explosives as the primary means of lethality. These include but are not limited to:                i) Addressing the high sensitivity of explosives to uncontrolled environmental effects such as heat, vibration, and impact;        ii) Launching a munitions system, specifically a warhead containing an explosive, without initiating the explosive;        iii) Initiating an explosive at an appropriate time and location in a target vicinity,        iv) Passing an explosive through and into a protected target without damaging the explosive and/or causing premature explosion.        
In order to address these issues, explosives-based munitions systems, and particularly warheads thereof, are typically encased with one or more structural materials (e.g. high strength steels) which protect the explosive and generally form part of the munitions structure. This configuration has the significant drawback that the munitions structure makes up a relatively large portion of the total weight of the munitions system in order to ensure viable protection for the explosive. As an example, it is not uncommon for a protective steel case to make up to 80% by weight of a given munitions system. This not only increases the overall weight of a munitions system but also complicates its transportation by air or fast moving light vehicles.
There are other complications with this conventional configuration. For example, the violent break-up of structural steel upon explosion of an explosive can cause uncontrolled fragment projectiles and collateral damage. Inertia and plastic deformation of a structural case during fragmentation also reduces the energy of explosives available for increasing ambient pressure and producing blast. This drawback requires the use of more explosives which in turn require more structural steel for protection, thus presenting undesirable limitations on the effectiveness of conventional munitions in compact packages.
Over the last two decades, a variety of reactive materials (RMs) have been developed in order to make explosive-based munitions less sensitive and require fewer explosives (i.e. less explosive material) while maintaining or improving the effectiveness of the munitions. RMs can be defined as a class of energetic solids that contain large amounts of enthalpic energy. These materials offer several advantages over traditional high explosives. These include insensitivity, lesser hazardous content, and energy output for longer times (>10 μs). Early RMs were mostly based on fluoropolymer binder metal composites such as aluminum filled with fluoropolymers. A major shortcoming of these reactive materials was the low density, which precludes them penetrating into targets. As a result, they could not be used as casing or liner material in munitions systems. These low-density materials especially lose their effectiveness on protected targets such as armored vehicles and structures.
Accordingly, fluoropolymers with high-density metals, such as tungsten (W), were developed to achieve higher density. Also, fluoropolymers with high-density reactive metals such as tantalum (Ta) and hafnium (Hf), were developed and offered improvements both in density and overall reactivity. There were also other efforts combining different reactive metals, such as Hf and aluminum (Al), with various sintering methods without fluoropolymer binders. One major issue for such hybrid materials is achieving uniform distribution of reactive metals in a matrix. The powder-based fabrication process of sintering methods results in the oxidation of reactive particles, thereby significantly reducing their energetic capacity.
Another critical shortcoming of known reactive materials is a lack of mechanical strength for structural durability. Structural components such as warhead liners are typically made of steel, a much higher strength material than reactive materials. In addition to being inadequate to serve structural purposes, known reactive materials have other deficiencies resulting from their low strength, such as the premature break-up of reactive material during launch and coupling to the target.
Accordingly, there is a need to reduce the overall content of munitions systems constituted by explosives. There is a further need to reduce the sensitivity of the explosive content while providing the desired chemical energy to produce rapid pressure increase. Furthermore, there is a need to reduce the parasitic weight of protective cases in munitions structures to increase lethality, especially in compact packages.